Investigation of the effect of dehydroepiandrosterone (DHEA), a steroid abundant in men and women between the ages of 20-30. DHEA is a nutritional supplement. The hypothesis is that DHEA production becomes the predominant source of androgens and estrogens in postmenopausal women, contributing to maintenance of bone mass and that supplementation with DHEA will decrease bone turnover. Association between lower DHEA levels and osteoporosis has been observed in post menopausal women. Bone remodeling, consisting of bone resorption followed by bone formation, is a continuous process in healthy bone required to maintain skeletal integrity. After peak bone mass at the age of 20-30 is reached, bone mass in all individuals begins to decline as resorption exceeds formation. In women, declining estrogen levels at menopause are associated with accelerated bone resorption leading to a 5-10 year period of rapid bone loss. Because of this period of rapid bone loss, a significant proportion of women develop osteoporosis. Because of the risks associated with estrogen replacement, many women choose not to take the therapy for a long term. Postmenopausal women between the ages of 65 and 70 with osteopenia (reduced bone mass) will be randomized into four groups. One group will receive a placebo, while the other three groups will receive various doses of DHEA. Participants will meet with the GCRC dietition to determine their calcium intake based on dietary history and given advice on how to increase dietary calcium and vitamin D. At the beginning of the study blood will be drawn to test for biochemical markers of bone turnover, osteocalcin, bone specific alkaline phosphatase, TRAP, and a urine NTX will be done. These will be repeated at two months and three months. Several other tests will be done at those times. Blood and urine samples will be taken in the morning after a 12 hour fast.